I would say, yes - if hostile means that soft or vague or undocumented posts are challenged politely and constructively. If posts are edited or closed or voted down, also then yes. This is such a place where polite disagreement and high level discussion is to be had in an adult manner. Your question here is a perfect example of that - questioning our entire motivation, philosophy, and culture.
It might get up votes and it might get down votes, but the discussion should be encouraged, welcomed and dignified. Disagreement is not hostility, so I hope you aren’t referring to that above, though, in your definition of hostile. (And I don’t think you are asking that, but you didn’t put in words or examples so I had to start somewhere.)
I would say no, we never should allow bullying or mean or personal challenges to remain. They will happen, but they should be aired, discussed and ultimately changed by the moderation tools. Moderation is comments, votes, edits and flags by everyone who has the reputation to moderate. It’s also flags and actions by those of us that are elected moderators and people who post on meta.
I also respect your making this vague and not posting specific examples of this behavior so we all can agree on the ideals and goals.
There should be a bright dividing line between something being critical and ok versus something being hostile and not ok. That line is our code of conduct.
Now, the world is full of grey and language and norms make one thing appear less like hostility to some, so we do all need to be open to someone mis-typing and not meaning harm on occasion. But if that happens after flags and after clarification - patterns of clear intent are no excuse to not engage to remove or correct clear violations of the code.
Please flag potential code violations each time you see them and unless we are declining your flags, keep on us. Now we don’t need 10 flags at once if one will do, but over time careful flagging is the best defense against hostility.
If you want to flag as other any cases of unkindness, hostility or just uncertainty - I am sure the mod team will reach out privately or publicly to ensure we address anything you see. A follow on question here on meta might be good as well if you want to ask how or why a certain post ended up where it is today.
I wouldn’t recommend flagging a post with less than 5 net down votes or flagging any one instance where comments are cleaned up or a post couldn’t be saved by an edit.